Problem: Simplify the following expression: $q = \dfrac{9}{5t} \div \dfrac{5}{10t}$
Answer: Dividing by an expression is the same as multiplying by its inverse. $q = \dfrac{9}{5t} \times \dfrac{10t}{5}$ When multiplying fractions, we multiply the numerators and the denominators. $q = \dfrac{ 9 \times 10t } { 5t \times 5}$ $q = \dfrac{90t}{25t}$ Simplify: $q = \dfrac{18}{5}$